JP2010020227A - Developer supply device and electrophotographic image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer supply device that has a discharge port for supplying a developer to a development device in the midway of a developer conveyance route, and prevents aggregation of the developer near the discharge port and reduces the increase in driving torque even when the discharge port is blocked by some cause. <P>SOLUTION: This developer supply device for supplying the developer to a development device used for an image forming device comprises a developer storage section for storing the developer, a developer conveying member that is disposed in the developer storage section and conveys the developer from one end towards the other end, a shielding member for shielding a part of the developer conveying member between it and the developer storage section, and the discharge port that is disposed in a vertically downward part in the region shielded by the shielding member and supplies the developer to the development device. The shielding member has communication ports to the developer storage section on the upstream and downstream sides of the feed direction of the developer with respect to the discharge port. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a developing device used in an electrophotographic image forming apparatus, a developer replenishing device that replenishes a developer to a process cartridge that can be attached to and detached from the electrophotographic image forming apparatus main body including the developing device, and an electrophotographic image forming apparatus. It is about.

  Here, the electrophotographic image forming apparatus forms an image on a recording medium using an electrophotographic image forming system. Examples of the image forming apparatus include, for example, an electrophotographic copying machine, an electrophotographic printer (for example, a laser beam printer, an LED printer, etc.), a facsimile apparatus and a word processor, and a multifunction machine (multifunction printer) thereof. .

  2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine, if it is used for a long time, replacement of an electrophotographic photosensitive drum, replacement of a developing device or supply of toner as a developer, cleaning of a charger, waste toner Replacement of the accumulated cleaning container and other adjustments around the photosensitive drum were necessary.

  Therefore, in the electrophotographic image forming apparatus using the electrophotographic image forming process, the electrophotographic photosensitive member and the process means acting on the electrophotographic photosensitive member are integrally formed into a cartridge, and the cartridge can be attached to and detached from the electrophotographic image forming apparatus. A cartridge system is adopted.

  Further, a system is employed in which a developer replenishing device containing developer is detachable from the image forming apparatus, and the process cartridge is replenished with respect to such a process cartridge. According to this system, since the life of the developer replenishing device that replenishes the developer consumed with use and the life of the process cartridge can be considered independently, the process cartridge and developer can be used more efficiently. can do.

In such a developer replenishing device, a constant amount of developer is discharged by a conveying member formed by a screw in order to stably replenish the process cartridge with the developer consumed by the process cartridge. Proposals have been made to stabilize the amount of developer to be discharged by conveying toward the outlet and discharging from the outlet. (For example, see Patent Document 1)
In addition, a developer circulation path is provided in which the developer is circulated in a space divided in the developer storage section, and a desired amount of developer is developed by providing a discharge port at a position off the developer circulation path. Some devices could be refilled. (For example, see Patent Document 2)
In a developer replenishing device used in an image forming apparatus, a toner seal for preventing a developer from leaking from a discharge port until a user uses the developer at a discharge port for supplying developer to the developing device. Is provided.
JP 2002-006601 A Japanese Patent Laid-Open No. 2003-66706

  However, if the toner seal is not pulled for some reason (for example, the user forgets to pull the toner seal), the developer is developed near the discharge port when the image forming apparatus is activated and the developer in the developer supply apparatus is transported. If the agent aggregates and the circulation becomes poor, the discharge port may be clogged, and the load of the driving torque of the developer supply device may increase. Therefore, in order to prevent overloading of the image forming apparatus, the image forming apparatus main body is provided with a torque overload detection mechanism that stops the image forming apparatus when the driving torque of the developer supply device exceeds a certain value. In contrast, an excessive load is prevented.

  An object of the present invention is to provide a special drive torque overload detection mechanism in the image forming apparatus main body by preventing excessive aggregation of the developer near the discharge port of the developer supply device and reducing an increase in drive torque. It is an object of the present invention to provide a developer replenishing device capable of avoiding an increase in driving torque of the image forming apparatus main body without doing so.

  In order to achieve the above object, according to a first aspect of the present application, there is provided a developer supply device for supplying a developer to a developing device used in an image forming apparatus, a developer storage portion for storing the developer, A developer conveying member that is provided in the developer accommodating portion and conveys the developer from one end to the other end; and a shielding member that shields a part of the developer conveying member from the developer accommodating portion. A discharge port for supplying developer to the developing device vertically below the region shielded by the shield member, and the shield member feeds the developer to the discharge port. A developer replenishing device having a first communication port with the developer storage unit on the upstream side in the direction and a second communication port with the developer storage unit on the downstream side.

  According to a second aspect of the present application, the first communication port is located in the axial direction of the developer conveying member, and the second communication port is located in a direction perpendicular to the axis of the developer conveying member. The developer replenishing device according to the first aspect of the invention.

According to a third aspect of the present application, the developer conveying member includes a first screw portion that conveys the developer from one end toward the discharge port;
A second screw part that conveys the developer from the discharge port toward the second communication port;
A developer replenishing device according to the first aspect of the present invention, further comprising a third screw portion that conveys the developer from the other end toward the second communication port.

  As described above, according to the developer replenishing device of the present invention, even when the user forgets to pull the toner seal or the like and the discharge port is blocked, toner circulation in the toner transport unit can be reliably performed. And an increase in driving torque of the developer conveying member can be prevented. Therefore, overloading of the image forming apparatus main body can be prevented without providing a torque overload detection mechanism.

  Next, details of the present invention will be described in accordance with the description of the embodiments.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

[Basic configuration of image forming apparatus main body]
A basic configuration of the image forming apparatus main body 1 will be described with reference to FIG. FIG. 1 is a schematic view of a multicolor image forming apparatus according to the present invention.

  The image forming apparatus main body 1 is provided with a storage unit 21 for storing the recording medium 20, a transport unit 22 for transporting the recording medium 20, and a storage unit 23 for storing the process cartridges 7 (7a, 7b, 7c, 7d). Yes. An exposure unit 24 (24a, 24b, 24c, 24d) for recording a latent image on the photosensitive drum 6 (6a, 6b, 6c, 6d) of the process cartridge 7 mounted in the storage unit 23 is formed on the drum. The primary transfer means 25 (25a, 25b, 25c, 25d) for primary transfer of the transferred image to the intermediate transfer means 26 is arranged in each color. Further, the intermediate transfer means 26 to which images on the drum are collectively transferred, the secondary transfer means 27 for transferring the developer transferred to the intermediate transfer means 26 to the recording medium 20, and the developer developed on the recording medium 20. A fixing device 28 for fixing the recording medium and a discharge unit 29 for discharging the recording medium are disposed.

  In image formation, when an image output signal is sent to the image forming apparatus main body 1, the photosensitive drum 6 is rotated. Next, a voltage is applied to the charging means 4 disposed around the photosensitive drum 6 so that the photosensitive drum 6 is uniformly charged. The exposure unit 24 selectively exposes the photosensitive drum 6 according to the image signal, and forms a latent image on the surface of the photosensitive drum 6. Next, the latent image formed on the surface of the photosensitive drum 6 is developed by developing the developer by the developing means 8. Next, the developer developed on the surface of the photosensitive drum 6 is transferred to the intermediate transfer unit 26 by the primary transfer unit 25. Here, the recording medium 20 stored in the storage unit 21 is transported to the secondary transfer unit 27 by the transport unit 22. Then, the developer on the intermediate transfer unit 26 is transferred to the recording medium 20 by the secondary transfer unit 27. Further, the recording medium 20 is conveyed by the conveying unit 22, and the developer is fixed to the recording medium 20 by heat and pressure in the fixing device 28, and then discharged to the discharge unit 29.

[Basic configuration of process cartridge]
A basic configuration of the process cartridge 7 will be described with reference to FIG. FIG. 2 is a schematic sectional view of a multicolor process cartridge according to the present invention, in which the process cartridge 7 and the toner cartridge 2 are separated.

  The process cartridge 7 includes a photosensitive drum 6, a cleaner unit 3 having a charging member 4 and a cleaning member 5, and a developing unit 9 having developing means 8, and is detachable from the image forming apparatus main body 1. It is.

  The photosensitive drum 6 is rotatably supported on the frame 3 a of the cleaner unit 3. A charging member 4 that charges the surface of the photosensitive drum 6 and a cleaning member 5 that collects the developer remaining on the photosensitive drum 6 without being transferred are disposed around the photosensitive drum 6.

  The developing unit 9 includes a developing unit 8 that develops a latent image formed on the photosensitive drum 6, and a developer storage container 9a that temporarily stores the developer in order to supply the developer to the developing unit. . The developer storage container 9a has a supply port 19 for supplying the developer in the toner cartridge 2 to the developer storage container 9a from the developer discharge port 15, and a developer storage amount in the developer storage container 9a. A developer storage amount detection mechanism 18 for detection is arranged.

[Removal of process cartridge and toner cartridge]
The attachment / detachment of the process cartridge and the toner cartridge will be described with reference to FIG. FIG. 3 is a perspective view in which the cartridge replacement door 30 is opened to detach the process cartridge 7 (7a, 7b, 7c, 7d) and the toner cartridge 2 (2a, 2b, 2c, 2d) from the image forming apparatus main body 1. is there. To attach and detach the process cartridge 7 and the toner cartridge 2, the cartridge replacement door 30 provided in the image forming apparatus main body 1 is opened, and the process cartridge 7 and the toner cartridge 2 are loaded and unloaded in the direction of arrow B in the figure with respect to the main body opening 31. Is done.

[Basic configuration of toner cartridge]
A basic configuration of the toner cartridge 2 will be described with reference to FIG. The toner cartridge 2 contains a developer accommodating portion 10 for accommodating a developer to be supplied to the process cartridge 7, a discharge port 15 for replenishing the developer, and transporting the developer to the discharge port 15. The image forming apparatus body 1 is detachable from the image forming apparatus main body 1.

[Configuration of toner cartridge]
A toner cartridge configuration according to the embodiment of the present invention will be described with reference to FIGS. 4, 5, and 6.

  4A is a cross-sectional view of the toner cartridge 2 as viewed from above, FIG. 4B is a perspective view of FIG. 4A, FIG. 5 is a cross-sectional view as viewed from the side, and FIG. It is sectional drawing. The toner cartridge 2 has a developer accommodating portion 10 that accommodates a developer to be supplied to the process cartridge 7 as a frame, and the developer is contained in the developer accommodating portion 10 from the first end 10a. A conveying member 11 having a screw shape for conveying to the two ends 10b is rotatably supported by the developer storage unit 10. The transport member 11 has a first transport screw 11a for transporting the developer from the first end 10a toward the discharge port 15, and a second transport screw for transporting the developer from the discharge port 15 to the communication port 16b. 11b and a third conveying screw 11c for conveying the developer from the second end 10b toward the communication port 16b. Further, a sheet-like elastic member 11 d for sending the developer from the discharge port 15 to the supply port of the process cartridge 7 is provided above the discharge port 15 of the conveying member 11.

  Further, a stirring member 12 that conveys the developer from the second end 10b to the first end 10a is rotatably supported by the developer storage unit 10. The stirring member 12 is formed of a stirring shaft 12a having a length from the second end 10b to the first end 10a, and a flexible sheet member 12b. The sheet member 12b is divided at regular intervals, and the respective leading ends in the rotational radius direction are inclined in the axial direction so that the sheet free length on the first end 10a side becomes long. Therefore, when the stirring member 12 rotates in the direction of arrow J in FIG. 6A, the tip of the stirring member 12 is twisted in the direction of arrow U in FIG. Thus, the stirring member 12 is configured to convey the developer in the direction of arrow T in FIG. 4A while stirring the developer, and collect the developer near the communication port 16a.

  Further, drive input units (conveyance drive input unit 11f and agitation drive input unit 12c) for driving the conveyance member 11 and the agitation member 12 by the driving force of the image forming apparatus main body are arranged on the end surfaces in the longitudinal direction of the developer storage unit 10, respectively. is doing.

  Next, a shielding member 13 for separating a part of the conveying member 11 from the developer accommodating portion 10 is installed in the developer accommodating portion 10. As shown in FIG. 6B, the shielding member 13 includes a tunnel portion 13a that covers the outer shape of the screw of the agitating member 11, and the developer on the shielding member 11 in the direction of the arrow K (FIG. 6B). ) Is formed by a slope 13b that leads to).

  Further, as shown in FIG. 5, in the developer transport path 14 shielded by the shield member 13, a discharge port 15 for replenishing the developer to the process cartridge 7 is installed below the transport member 11 in the vertical direction. ing.

  The shielding member 13 communicates with the developer transport path 14 and the developer storage portion 10 through a communication port 16 a formed upstream of the discharge port 15 in the developer feeding direction. On the downstream side in the agent feeding direction, the developer conveyance path 14 and the developer storage unit 10 are communicated with each other through the communication port 16b.

  A developer transport path in a short cross section will be described with reference to FIG. 6A is a cross-sectional view of a region where the shielding member 13 is not installed, FIG. 6B is a cross-sectional view of the vicinity of the discharge port 15, and FIG. 6C is a cross-sectional view of the vicinity of the communication port 16b.

  In the region shown in FIG. 6A, after the developer in the developer storage unit 10 is sent to the transport member 11 side by the rotation of the stirring member 12, the developer is transported toward the communication port 16 a by the rotation of the transport member 11. Is done. In the region shown in FIG. 6B, the developer sent into the developer transport path 14 is sent out by a certain amount toward the discharge port by the elastic member 11d. In the region shown in FIG. 6C, excess developer in the developer transport path 14 is returned to the developer storage unit 10 from the communication port 16.

  In addition, a toner seal 17 for sealing the discharge port is provided outside the discharge port 15 in order to prevent the developer from leaking from the discharge port 15 until the user uses it. The toner seal 17 is welded at a welded portion 17a outside the frame body, is folded back at the folded portion 17b in the middle of the toner seal 17, and the pulling portion 17c at the tip of the toner seal 17 is pulled. It comes to communicate with the replenishment port 19.

  Next, the operation will be described.

  First, the basic operation of developer conveyance will be described with reference to FIGS.

  As shown in FIG. 4, the developer stored in the developer storage unit 10 is conveyed in the direction of the communication port 16a (direction of arrow T in FIG. 4) while being stirred by the operation of the stirring member 12. The neighborhood is filled with developer.

  As shown in FIG. 2, when the image forming apparatus body 1 detects that the developer in the process cartridge 7 has been reduced by the developer storage amount detection mechanism 18 in the process cartridge 7, the conveyance drive input unit 11 f of the toner cartridge 2 and the agitation are mixed. Drive is transmitted to the drive input unit 12c. When the conveying member 11 is actuated by driving here, as shown in FIG. 5, the developer in the vicinity of the communication port 16a is conveyed by the first conveying screw 11a by a certain amount in the direction of the arrow C. The developer conveyed to the vicinity of the discharge port 15 is discharged from the discharge port 15 by a predetermined amount by the elastic member 11d as indicated by an arrow D, and is supplied to the process cartridge 7.

At this time,
Excess developer remaining in the vicinity of the discharge port without being discharged from the discharge port 15 is further transported to the back of the developer transport path 14 by the second transport screw 11b as shown by an arrow E in FIG. Here, since the developer transported to the second end 10b is returned in the direction of arrow F in FIG. 5 by the third transport screw 11c, the transport direction at the boundary between the second transport screw 11b and the third transport screw 11c. Is pushed out in the vertical direction (arrow G direction), and returned to the developer accommodating portion 10 from the communication port 16b. As described above, the operations of the agitating member 12 and the conveying member 11 can stably supply the process cartridge 7 without aggregating the developer. Further, even when the discharge port 15 is blocked due to vibration during transportation, forgetting to draw a seal, etc., the developer is prevented from excessively aggregating in the vicinity of the discharge port 15, and an increase in driving torque is avoided. It is possible to prevent the torque for driving the conveying member 11 from rising abnormally.

1 is an overall view of an image forming apparatus according to the present invention. 1 is an overall view of a toner cartridge and a process cartridge in the present invention. FIG. 2 is a schematic perspective view in which a cartridge replacement door for attaching and detaching a process cartridge from the image forming apparatus main body in the present invention is opened. 1 is a cross-sectional view and a cross-sectional perspective view of an embodiment of a toner cartridge according to the present invention. 3 is a cross-sectional view of an embodiment of a toner cartridge according to the present invention. FIG. FIG. 3 is a short cross-sectional view of an embodiment of a toner cartridge according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus main body 2 Toner cartridge 3 Cleaner unit 3a Frame body 4 Charging member 5 Cleaning blade 6 Photosensitive drum 7 Process cartridge 8 Developing means 9 Developing unit 9a Developer storage container 10 Developer storage part 11 Transport member 11a First transport Screw 11b Second conveying screw 11c Third conveying screw 11d Elastic member 11f Conveying drive input section 12 Stirring member 12a Stirring shaft 12b Sheet member 12c Stirring driving input section 13 Shielding member 13a Tunnel section 13b Slope 14 Developer conveying path 15 Discharge port 16a , 16b Communication port 17 Toner seal 17a Welding portion 17b Folding portion 17c Pulling portion 18 Developer storage amount detection mechanism 19 Supply port 20 Recording medium 21 Storage portion 22 Transport portion 23 Cartridge storage portion 24 Exposure portion 25 One Next transfer unit 26 Intermediate transfer unit 27 Secondary transfer unit 28 Fixing unit 29 Ejecting unit 30 Cartridge replacement door 31 of main body of image forming apparatus Main unit opening

Claims (4)

In a developer supply device for supplying a developer to a developing device used in an image forming apparatus,
A developer accommodating portion that accommodates the developer, a developer conveying member that is provided in the developer accommodating portion and conveys the developer from one end to the other end, and a part of the developer conveying member is the developer. A shielding member that shields between the housing portion, and a discharge port for replenishing the developer to the developing device vertically below the region shielded by the shielding member;
The shielding member has a first communication port with the developer storage unit on the upstream side in the developer feeding direction with respect to the discharge port, and a second communication port with the developer storage unit on the downstream side A developer replenishing device comprising:   The first communication port is positioned in an axial direction of the developer transport member, and the second communication port is positioned in a direction perpendicular to the axis of the developer transport member. Developer replenisher. The developer conveying member includes a first screw part that conveys the developer from one end toward the discharge port;
A second screw part that conveys the developer from the discharge port toward the second communication port;
The developer replenishing device according to claim 1, further comprising a third screw portion that conveys the developer from the other end toward the second communication port.   4. An electrophotographic image forming apparatus comprising the developing device and the developer replenishing device according to any one of claims 1 to 3, wherein the developer is replenished to the developing device.

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